Field of the Invention
The present invention relates to a LED package in which a plurality of light-emitting devices are mounted on a substrate and those light-emitting devices are sealed with a sealing resin mixed with phosphor, and more particularly, to a LED package having a characteristic in a heat sink pattern on a rear surface of the substrate.
Background Art
A LED package is widely known as a white light source for illumination or backlight, in which a plurality of Group III nitride semiconductor blue light-emitting devices are mounted on a substrate and those light-emitting devices are sealed with sealing resin mixed with yellow phosphor. This LED package achieves white light emission by converting a part of blue light emitted from the light-emitting device into yellow light with yellow phosphor, and mixing the yellow light and the blue light emitted from the light-emitting device.
Since such a LED package is driven by a large current, heat generation from the light-emitting device is large, and it is necessary to efficiently radiate heat to the outside. For example, a heat sink is provided on the rear surface of the substrate in the LED package so that heat is efficiently conducted via solder from the heat sink to the mounting substrate when the LED package is mounted via solder to the mounting substrate.
Japanese Patent Application Laid-Open (kokai) No. 2009-123853 discloses a LED package in which a light-emitting device is sealed with a phosphor-dispersed glass by hot press processing, and describes that there is provided a heat sink divided into a plurality of heat sinks by striped grooves. Such grooves can discharge the gas produced by vaporization of residue such as resist during hot press to the outside, thereby preventing the heat sink from protruding.
Japanese Patent Application Laid-Open (kokai) No. 2013-12531 describes an electronic device provided with a heat radiation member just below the electronic parts in the LED package.
When the rear surface of the LED package and the mounting substrate are joined via solder, gas is emitted from solder, air bubbles are generated between the solder and the heat sink so that a bonding area between the solder and the heat sink is reduced. There was a problem of deterioration in heat radiation performance.
Moreover, the LED package of Japanese Patent Application Laid-Open (kokai) No. 2009-123853 was inappropriate to efficiently discharge the gas generated from solder to the outside because the grooves dividing the heat sink are formed in a stripe pattern.